Opening a new browser window in Action

I wrote some JavaScript that opens a new browser window. Works fine. In that browser window, I display a PDF.

The question I keep getting is why didn't I use some "struts" mechanism to open a new browser window. My thinking is that Struts is limited to the HTTP protocol and thus can't do what Javascript can do on the client side (like open a new window...).

Is this correct or is there a way to open a completely new browser window on the client from, say, an Action method in Struts?

Javascript is a client side scripting, where as Struts Action and/or Servlets/JSP is at server side. So obviously, there is no way one can control browsing window from the code that would run purely at the Server in this case Struts. Some fragement should run at client side to make this happen.